Swapping homework answers may be the worst-kept secret among college students and professors, but this casual dishonesty has a very serious outcome, a new study shows.

Researchers at the Massachusetts Institute of Technology found that cheating on homework has a much greater impact on student performance than both students and professors may realize.

A news release from M.I.T. explains how a team headed by physicist Dr. David E. Pritchard tracked response times of students completing algebraic equations within a web-based learning environment. When students answered too quickly, the results were flagged as possible cheating.

The team found that students required to solve similar problems at exam time consistently scored two letter grades below their non-copying counterparts. They also determined that repeat offenders, students who copy over 30 percent of their answers, fail at three times the rate of the overall student population.

The Center for Academic Integrity, cited in The Chronicle of Higher Education, finds that 22 percent of students admit to cheating on a test, but 43 percent report engaging in "unauthorized collaboration" on homework outside of the classroom. "Homework copying is severely impeding students' learning, and teachers don't take it seriously enough," says Dr.Pritchard in ScienceNews. "It's a killer for the grades and a killer for the students."

Unfortunately, many students don't see it as wrong, especially if they are finding answers online instead of in another classmate's work. "I call it 'technological detachment phenomenon,'" said Trevor Harding, a professor of materials engineering at California Polytechnic State University at San Luis Obispo in the Chronicle of Higher Education. Harding has researched cheating in engineering programs. "As long as there's some technology between me and the action, then I'm not culpable for the action."

Pritchard and his team were also interested in why students at M.I.T., one of the best schools in the country, would feel the need to cheat. "People believe that students copy because of their poor academic skills," says Young-Jin Lee, assistant professor of educational technology at KU and a contributor to the M.I.T. study, in the Epoch Times. "But we found that repetitive copiers-students who copy over 30 percent of their homework problems-had enough knowledge, at least at the beginning of the semester. But they didn't put enough effort in. They didn't start their homework long enough ahead of time, as compared to noncopiers."

Students in large, lecture-based courses are especially susceptible to indulging in this kind of cheating where there isn't much one-on-one with the professor. The M.I.T. news release states that Dr. Pritchard reduced copying by changing his class format from lecture-based to a "technology-enabled active learning format" which involves more contact between students, teachers and teaching assistants as well as reducing the student-to-staff ratio.

The Chronicle of Higher Education states that with lecture classes, Pritchard detected cheating on about 11 percent of homework problems, the number has dropped to 3 percent. He also shares the study's findings with his students, to stress the value of completing their own homework.